Die casting and method of producing same



july 30, l929. W 1 DURlNG Lzz DIE CASTING AND METHOD OF PRODUCING SAME Filed Nov. 17, 1925 J 3 E 9% 'y reigned' July 30, 1929."

UNITED STATES PATENT OFFICE.`

'WILLIAM J'. DURING, OF SYR-ACUSE, NEW YORK, .A S'SIGNOR TO PRECISION CASTINGS- COMPANY INC., FAYETTEVILLE, NEW YORIIQACORPORATION OF NEW YORK.

DIE Gesteine AND METHOD oF rRonUcmG SAME.

Application mea November? 17, 1925,' serial No. 69,604.

This invention relates to certain new and useful improvements in die-castings and the method of producing dic-'castingsl s Heretofore it has been customary to for'm die-castings and die-cast articles of a solld body of solne metal or alloy suitable for. die- 'casting Such articles are' comparatively heavy and the metal is relatively expenslve.

I have discovered that al'tho the metal is shot into the die under high pressure and at a very high temperature','for instance 90() deg. centigrate, or higher, that it is possible to support a core 'or cores of Wood Within the die insuch a 'manner that a vshell of metal of f desired thickness will he cast around itso as to iill the space Within the' die outside the core, without the Wooden core being consumed or appreciably affected altho under ordinary circumstances molten metal at such high temperatures ,would be destructive of the core. This result is accomplished doubtless by reason of the fact that the -application of the metal coating to the Wooden core is so instantaneous and with practical absence of sufficient oxygen to sustain combustion and cooling of the metal is so rapid that the wooden core is practically unaffected, eX- cept perhaps for a slight charring upon the exterior surface. V

In fact, the grain of the Wood seems to he imprinted on the inner surface of the metal shell as a result of the extremely close assolciation of the metal and the Wooden core, and the metal seems to enter the pores of the Wood resulting in a substantial adhesion or cohesion of the same substances;

The product is greatly improved in that it is much lighter than a solid metal product and-further, and perhaps more important,

a substantial saving in met-al is effected, and.

thereby a saving in cost as the, wooden insert is considerably less expensive than the metal which it displaces.

Further, for many purposes the Wooden insert has advantages, as for instance when it -is desired to secure other parts to the diecasting. A Further, the Wooden core lends itself to the production of certain die-cast articles of required strength that could be produced with great diiiiculty, if at all, by the usual 4diecasting process.

somewhat different die-cast article including an enclosed wooden core. v

Figure illustrates the article produced by the apparatus of Figure 4. 4

The die-cast article shown in Figure' is designed for such a use, as for instance adapted to-constitute-a portion of a vacuum cleaner,

that eye-members -1- are required at its opposite ends. It is practically impossible to die-,cast such a completed article by present 'methods which shall have the required strength. Y f

The method of this application among other advantages, is peculiarly adapted for such product/ion, and the same'may be ca rried out as follows Itis important 'that the Wooden core be thoroughly dried' and practically all the moisture be removed therefrom so that little if any shrinkage will result when the product is completed. A dry wooden core 2 of desired shape is formed andordinary screw-eyes 3,- are threaded into its opposite ends so that the eyes project from the Wooden core;4 The die .-3- is here formed with recesses outside the chamber in which the casting is to be formed for lreceiving these eyes, and the eyes may be supported as illustrated in Figures 1 and 2 vupon pins the die which is o'f sectional character held v together 1n any suitable Way and instantaneously forms itself .asY a coating upon the outer surface ofthe wooden insert -,2,-,' and attaches itself to the shank portions of the screw eyes that are-positioned in the die-chamber, the eyes 1-1 being themvmetal, provide a much stronger and more substantial structure than if the whole arti'- cle were formed of die-cast metal, even were that practical. l

The invention has many adaptations, as

for instance in the die-'casting of knobs or handles for various uses. For illustration, the knob of a transmission lever, as shown in Fig. 5, the method of manufacture of `which is illustrated in Figure 4.

Suitable dies having been formed, a dry 'piece of Wood -8- for this purpose perhaps preferably'of spherical shape is inserted Within the die. This wooden core is formed with a cylindrical recess l0- which receives the reduced cylindricalend of a stud -9- fitting the recess, `whereby'the core isv `supported `within the die. The enlarged portion of the stud contacts with the core -8- and extends outwardly through the enclosing space and the die. By this means the core is effectively supported and a cylindrical recess vis formed within the completed article which adapts itself for ready attachment to various articles. The enlarged portion of the shank -9- that eX- tends outwardly through the enclosing space within the die forms a circular opening bllin the enclosing spherical casing -12- of die-cast metal and for the particular purpose that this article is designed, the opening -11- is of somewhat greater diameter than the recess -10-, but obviously this is variable at will in the-production of a desired form and shape of article. With the core supported as illustrated in Figure 4, the metal is shot into the die and forms around the Wooden core -8- a spherical casing of die-cast metal of desired thickness, which in ing -11-.

this illustration is broken only by the open-l It Will be obvious that the `core ,-8- may be of any desired size so that the enclosing layer of die-cast metal may be fof desired thickness. v

Altho I have shown and described specific articles and specific methods of their manu-v facture, -it will be obvious that this method adapts itself to the production of variousy articles of many and varied forms and shapes, and I do not desire to limit myself to any particular method of their manufacture or to any particular articles or' forms of the same, or thickness of the layer of metal cast about the core, except as the same may be specifically included in the claims hereto` appended.

l. The method of producing` a die-cast article comprising supporting a wooden core Within a die and spaced from the walls thereof, forcing molten die casting metal at a temperature above 1000 degrees F. into the die under such high pressurea's to surround the core with a coating of die-cast metal With lsufficient rapidity to prevent. combustion of the core.

2. As an article of manufacture, a shell of die cast metalv having a melting point higher than the combustion point of wood, and a wooden core permanently positioned in said shell in intimate contact. vtherewith throughout the inside surface of the shell.

3. The method of producing a die cast article comprising supporting a Wooden core within a die and spaced from the walls thereof, and forcing molten die casting metal at a temperature higher than the combustion point of Wood into the die under high pressure.

4.. As a new article of manufacture, a shell of'die cast metal having a melting point above 1000 degrees F. and a Wooden core permanently and wholly enclosed Within said shell and having its outside surface in intimate contact with the interior surface of i the shell.

In Witness whereof I have hereunto set my hand this 6th day of November, 1925.

WILLIAM -J DURING. 

